Sprayer

ABSTRACT

A sprayer is adapted to suction a liquid under back pressure and squirt the liquid in the atomized form from the nozzle by applying a pressure to the liquid. The sprayer comprises a sprayer body having a suction pipe and a cylinder communicating with the suction pipe, and a cylindrical projection extending from the closed end toward the open end of the cylinder and communicating with the suction pipe. A piston is slidably mounted to the sprayer body in a manner to surround the cylindrical projection. The piston defines such a liquid chamber that when the piston is moved into closest proximity to the closed end of the cylinder the volume of the liquid chamber is made minimal. As a result, when the piston is so moved, a liquid within the chamber is squirted efficiently at high pressure.

[ Oct. 21, 1975 SPRAYER [76] Inventor: Tetsuya Tada, 1339 Nishitakadomari, Onoda, Yamaguchi, Japan [22] Filed: Sept. 9, 1974 [21] Appl. No.: 504,287

[30] Foreign Application Priority Data Dec. 12, 1973 Japan 48-142124 [56] References Cited UNITED STATES PATENTS 7/1973 Boris 239/321 3,770,206 11/1973 Tada 3,797,749 3/1974 Tada 239/321 FOREIGN PATENTS OR APPLICATIONS 2,042,690 3/1972 Germany 239/375 910,791 11/1962 United Kingdom 222/383 Primary Examiner-Robert S. Ward, Jr.

[57] ABSTRACT A sprayer is adapted to suction a liquid under back pressure and squirt the liquid in the atomized form from the nozzle by applying a pressure to the liquid. The sprayer comprises a sprayer body having a suction pipe and a cylinder communicating with the suction pipe, and a cylindrical projection extending from the closed end toward the open end of the cylinder and communicating with the suction pipe. A piston is slidably mounted to the sprayer body in a manner to surround the cylindrical projection. The piston defines such a liquid chamber that when the piston is moved into closest proximity to the closed end of the cylinder the volume of the liquid chamber is made minimal. As a result, when the piston is so moved, a liquid within the chamber is squirted efficiently at high pressure.

8 Claims, 2 Drawing Figures US. Patent Oct.21,1975 I 3,913,841

SPRAYER BACKGROUND OF THE INVENTION This invention relates to a sprayer and particularly a manual sprayer adapted to suction a liquid and squirt the liquid in the atomized form from a nozzle.

A sprayer of this type is so designed that a piston is urged outward under the biasing force of a spring to cause a back pressure to be created within a cylinder to permit a liquid to be suctioned within the cylinder and the liquid is squirted in the atomized form from a nozzle by forcing the piston into the cylinder by virtue of a lever to cause a pressure to be applied to the fluid. The sprayer has a first valve operative to permit a flow of liquid into the cylinder and a second valve operative to permit a flow of liquid toward the nozzle. Since,

however, a clearance is left in a chamber defined within the cylinder when the piston is forced into the cylinder, a liquid within the chamber defined between the first and second valves is not completely discharged and, as a result, a relatively large amount of liquid is still left within the chamber. It is therefore impossible to squirt the liquid, efficiently at high pressure, from the nozzle.

SUMMARY OF THE INVENTION It is accordingly the object of this invention to provide an improved sprayer capable of squirting a liquid efficiently and at high pressure from a nozzle by discharging substantially all the liquid within a chamber defined between a first valve and a second valve.

According to this invention, the sprayer has a cylindrical projection extending from the closed end toward the open end of a cylinder. The piston has such a liquid chamber that when the piston is moved into closest proximity to the closed end of the cylinder the volume of the piston is made minimal. Consequently, when the piston is forced into the cylinder, the cylindrical projection substantially completely occupies the liquid chamber to cause substantially all the liquid within the chamber to be discharged through the second valve. It is therefore possible to squirt the liquid in the atomized form from a nozzle efficiently at high pressure.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross section showing a sprayer according to an embodiment of this invention in which a piston is extended outward; and

FIG. 2 is a fragmentary, enlarged cross-sectional view of the sprayer of FIG. 1, showing the state in which the piston is moved into closest proximity to the closed end of a cylinder.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT In FIG. 1, reference numeral 1 shows a body of a sprayer and 2 is a container mounted to the body of the sprayer and having a liquid sealed therein. The body of the sprayer 1 has a connecting section 3, a suction pipe 4 having one end extending into the container 2 to permit the liquid to be suctioned therethrough, and a cylinder 5 disposed on the side opposite to the side on which the suction pipe 4 is positioned and in a manner to communicate with the suction pipe 4. The cylinder 5 has a closed end 5a and an open end 5b. A piston 7 is reciprocably mounted relative to the cylinder 5 and slidably moved by a lever 6 relative to the cylinder 5. The connecting section 3 of the sprayer body is flared outward to provide a tapered inner surface 3a and has a plurality of axial slits 3b which extend inward from the end thereof to permit the end portion of the connecting section to be resiliently expanded outwardly. An annular fitting 8 is fitted over the outer periphery of the end portion of the connecting section 3. The annular fitting has an internal thread 8a removably screwed in an air tight fashion over an external thread 9a provided on a neck portion 9 of the container 2. Reference numeral 10 shows a seal having a tapered surface on its outer periphery which corresponds to the tapered surface 3a of the connecting section. The seal 10 is flanged at its one end where a plurality of concentric grooves 10a triangular in cross section are provided. The flange of the seal 10 has a sealing portion 10b which extends in the axial direction of the seal.-

When one end portion of the annular fitting 8 is fitted over the free end portion of the connecting section 3 with the insert inserted into the connecting section and the internal portion 8a of the annular fitting 8 is screwed over the external thread 9a of the neck portion of the container 2, the crests of the grooves 10a of the insert 10 are abutted against the neck end of the container 2, while the extending portion 10b of the insert 10 is intimately pushed against the inner surface of the annular fitting 8. As a result, a positive sealing is assured between the connecting section 3 and the annular fitting 8.

A bore 11 is provided on the closed end 5a side of the cylinder 5 of the sprayer body 1. The bore 1 1 communicates with the suction pipe 4. A hollow cylindrical projection 12 is integrally mounted at the closed end 5a of the cylinder and communicates with the bore 11. A cylindrical abutting member 13 is mounted at the forward end of the cylindrical projection 12 and has a plurality of grooves 13a provided in the inner surface thereof. The outer diameter of the enlarged portion of the abutting member 13 is substantially equal to the outer diameter of the cylindrical projection 12. A first valve 15 is movably disposed within a space 14 defined between the cylindrical projection 12 and the abutting member 13. The position in which the first valve 15 is located may be suitably selected. For example, the first valve may be located within a clearance defined at that portion where the suction pipe is connected to the cylinder 5. To squirt the liquid efficiently at high pressure, however, it is preferred that the first valve 15 be positioned within the space defined at the forward end of the cylindrical projection. Since the first valve 15 is so disposed, if it is contacted with the opening of the bore of the cylindrical projection 12, a flow of the liquid through the suction pipe 4 is prevented. On the other hand, even when the first valve 15 is contacted with the end of the abutting member 13, the liquid can be continuously suctioned through the grooves 13a.

The piston 7 is so mounted as to be slidably movable relative to the cylinder 5. The piston 7 includes an outer member 16 having one end portion threaded on the outer periphery thereof, an inner member 17 fitted over the other end portion of the outer member 16, and a cap member 18 having a nozzle 18a. A first compression spring 19 is disposed between the inner end of the inner member 17 and the closed end 5a of the cylinder 5 so that the piston 7 is urged outward from the cylinder 5. The inner member 17 of the piston 7 defines a liquid chamber or first valve chamber 20 therein. The first valve chamber 20 is so dimensioned that, when the piston 7 is slidably moved into closest proximity to the closed end a of the cylinder 5, the volume of the chamber is made minimal due to the presence of the cylindrical projection 12. If the chamber 20 is so occupied by the cylindrical projection 12, all the liquid, except for the liquid occupied in a position where the first spring 19 is disposed, trapped within the chamber is compressed to cause the liquid to flow through a passage 21. Consequently, the liquid can be ejected efficiently at high pressure and only an extremely small amount of liquid is left within the chamber. The inner member 17 may have a cylindrical extension 22 formed on the passage 21 side and extending toward the abutting member 13. The cylindrical extension 22 has an outer diameter slightly smaller than the inner diameter of the first spring 19. When the piston 7 is slidably moved relative to the cylinder 5, the cylindrical extension 22 is abutted against the abutting member 13 to cause the liquid to be squirted efficiently at high pressure. The presence of the cylindrical extension makes the sliding distance of the piston 7 small. The outer periphery of the open end portion of the inner member 17 is intimately fitted within an annular space 23 defined between the inner surface of the cylinder 5 and the outer periphery of the cylindrical projection 12. The inner member 17 is flared radially outward to provide a sealing portion 17a. The sealing portion 17a of the inner member [7 permits the liquid to be ejected efficiently at high pressure with no liquid left at the annular space 23. At the open end of the inner member 17 an annular groove 17b V- or U-shaped in cross section is preferably made. At the closed end 50 of the cylinder 5 a projection 5c corresponding in shape to the annular groove 17b is provided. When the piston 7 is moved inwardly relative to the cylinder 5, the annular groove 17b of the piston is fitted over the projection 5c to cause the sealing portion 170 to be forced radially outward, thereby assuring a complete sealing.

The passage 21 communicates with a second valve chamber 24 defined within the outer member 16 of the piston 7. Within the chamber 24 is disposed a second valve 25 for permitting a flow of the liquid passed through the passage 21. At the forward end of the outer member 16 a swirl imparting member 26 is fitted to impart a swirling movement to the liquid. Since a second compression spring 27 is disposed between the second valve 25 and the swirl imparting member 26, the second valve normally closes the passage 21. The second valve 25 has a rod 25a extending through the passage 21 into the chamber 20. The rod 25a is so dimensioned that it is intimately fitted into the bore of the abutting member 13 without leaving any clearance. As a result, the liquid can be ejected, efficiently at high pressure, through the second valve 25.

The nozzle 18a is provided at the forward end of the cap member 18. A plurality of bores 26a are provided in the end wall of the swirl imparting member 26 so that a swirling movement can be imparted to the liquid. An annular groove 26b is formed at the forward end of the swirl imparting member 26. The member 26 has at its forward end a sealing portion 26c which is intimately fitted into the cap member 18 to assure a liquidtightness between the cap member 18 and the member 26. A variable squirting angle of liquid can be provided by adjusting the position in which the cap member 18 is screwed into the outer member 16 and thus adjusting the distance between the member 26 and the cap member 18.ln FIG. 1, reference numeral 28 indicates a pivotal member around which the lever 6 mounted to the sprayer body 1 is swung; 29 an anchor pin extending from the inner wall of the lever 6 and fitted into the bore of the piston 7 to permit the piston 7 to be slidably moved; and 30 a cavity provided to obtain a shrinkage allowance.

There will now be explained the operation of the sprayer.

When the lever 6 is pulled in a direction indicated by an arrow A, the piston 7 is moved, against the urging force of the first spring 19, relative to the cylinder 5 as shown in FIG. 2. At this time, the first valve 15 is pressed by a fluid pressure on the cylindrical projection 12 to prevent a flow of liquid through the bore 11 into the first valve chamber 20. Upon continued compression, the fluid trapped within the chamber 20 causes the second valve 25 to be opened against the second spring 27 to permit the liquid to flow through the passage 21 into the second chamber 24. The fluid flowing into the second valve chamber 24 flows through the bores 26a of the swirl imparting member 26 and is subject to a swirling movement by the annular groove 26b and squirted, in the atomized form, from the nozzle 18a. At this time, the rod 25a is fitted into the abutting member 13 with a slight clearance left therebetween, while the extension 22 is abutted against the abutting member 13. As a result, substantially all the liquid trapped Within the first chamber 20 is compressed at high pressure and flows efficiently away from the first chamber 20. Since, at the same time, the piston 7 is inserted into the annular space 23 between the cylindrical projection 12 and the cylinder 5 with a slight clearance left, there is no room for the liquid to be occupied. If the liquid is compressed at high pressure, the elastic sealing portion 17 a of the piston 7 is urged radially outward, thus assuring a positive seal. Since the annular groove 17b is fitted over the projection 50 to cause the sealing portion 17a to be forced radially outward, there is no danger of leakage even if a high pressure liquid is involved.

Upon release of the lever 6 after the liquid has been squirted from the nozzle 18a, the lever 6 is swung, under the urging force of the first spring 19, in a direction indicated by B to cause the piston 7 to be returned to the original position. This induces a back pressure at the first chamber 20. As a result, the second valve 25 is caused to be moved so as to close the passage 21, while the first valve 15 is caused to be moved toward the abutting member 13 to permit the liquid to flow through the suction pipe 4 and bore 11 into the first valve chamber 20. Upon the repeated operation of the lever 6, the liquid within the container 2 is squirted, in the atomized form, from the nozzle.

FIG. 2 shows the state in which the liquid within the first valve chamber 20 and annular space 23 is completely discharged. In this state, the second valve 25 is urged, by the second spring 27, into contact with the inner end of the outer member 16. Where the sprayer is put in an inoperative state, for example, for display in the shop-window, the lever is swung in the direction indicated by A to the position where the rod 25 extends through the abutting member 13 into abutting engagement with the first valve 15 as shown in FIG. 2. In this state, a flow of the liquid into the first valve chamber 20 is prevented. Once this state is maintained in the known method, no leakage occurs even when the sprayer is inadvertently dropped.

As already mentioned above, according to this invention the cylindrical projection is provided at the closed end of the cylinder and the piston has the liquid chamber into which the cylindrical projection is inserted without leaving any clearance. Consequently, when the piston is moved into closest proximity to the closed end of the cylinder, the annular space between the outer surface of the cylindrical projection and the inner surface of the cylinder is substantially occupied by the wall of the piston with the grooved end of the piston fitted over the associated projection on the closed end of the cylinder, while the extension of the inner member is abutted against the abutting member with the rod fitted into the associated bore of the abutting member. As a result, all the liquid within the liquid chamber is discharged efficiently at high pressure, since there is left no room for the liquid to stay in the liquid chamber. This effect is further facilitated, since the first valve is so located in proximity to the first valve chamber as to make minimal an amount of liquid present therebetween.

The sprayer is all made of plastics except for springs. However, it may be made of other material as required, taking a strength, cost etc. into consideration.

The above-mentioned embodiment is shown only by way of example. Numerous changes and modifications may be made without departing from the concept of this invention. It should be noted that these will be encompassed within the spirit and scope of this invention.

What is claimed is:

l. A sprayer comprising a sprayer body having at one end a suction pipe and at the other end a cylinder communicating with the suction pipe and having an open end and closed end; a cylindrical projection mounted on the closed end of the cylinder in a manner to extend toward the open end of the cylinder, and communicating with the suction pipe; a first valve disposed within the spray body to permit a flow of liquid from the suction pipe; a piston slidably movable along the inner surface of the cylinder and surrounding the cylindrical projection, said piston including a cap member mounted at the forward end portion of the cylinder and having a nozzle, and a liquid chamber defined therein to permit the liquid to flow through the first valve, said liquid chamber being so dimensioned that when the piston is moved in closest proximity to the closed end of the cylinder the cylindrical projection makes the volume of the liquid chamber minimal; and a second valve disposed within the piston to allow the liquid to flow from the liquid chamber toward the nozzle.

2. A sprayer according to claim 1 in which said piston has an annular extension extending toward the cylindrical projection.

3. A sprayer according to claim 2 in which an annular abutting member against which said extension is abutted when the piston is slidably moved relative to the cylinder is further provided at ,the forward end of the cylindrical projection; and said first chamber is disposed within aspace defined by the end portion of the cylindrical projection and the abutting member.

4. A sprayer according to claim 3 in which said second valve has a rod extending through the extension of the piston and is operative to urge the first valve toward the abutting member when the piston is moved into closest proximity to the closed end of the cylinder.

5. A sprayer according to claim 4 in which said piston has a peripheral wall by which an annular space between the cylinder and the cylindrical projection is made minimal when the'piston is moved into closest proximity to the closed end of the cylinder.

6. A sprayer according to claim 5 in which said piston has at one end thereof an outwardly flared sealing portion and annular groove and said cylinder has at the closed end thereof an annular projection adapted to be fitted into the annular groove to push the sealing portion outward.

7. A sprayer according to claim 1 in which a swirl means is further provided adjacent to the cap member, said swirl means defining another liquid chamber between the second valve and the cap member and imparting a swirling movement to the liquid.

8. A sprayer according to claim 7 in which said cap member is slidably mounted at the forward end portion of the piston whereby when the distance between the swirl means and the cap member is adjusted the angle at which the liquid is squirted from the nozzle is varied. 

1. A sprayer comprising a sprayer body having at one end a suction pipe and at the other end a cylinder communicating with the suction pipe and having an open end and closed end; a cylindrical projection mounted on the closed end of the cylinder in a manner to extend toward the open end of the cylinder, and communicating with the suction pipe; a first valve disposed within the spray body to permit a flow of liquid from the suction pipe; a piston slidably movable along the inner surface of the cylinder and surrounding the cylindrical projection, said piston including a cap member mounted at the forward end portion of the cylinder and having a nozzle, and a liquid chamber defined therein to permit the liquid to flow through the first valve, said liquid chamber being so dimensioned that when the piston is moved in closest proximity to the closed end of the cylinder the cylindrical projection makes the volume of the liquid chamber minimal; and a second valve disposed within the piston to allow the liquid to flow from the liquid chamber toward the nozzle.
 2. A sprayer according to claim 1 in which said piston has an annular extension extending toward the cylindrical projection.
 3. A sprayer according to claim 2 in which an annular abutting member against which said extension is abutted when the piston is slidably moved relative to the cylinder is further provided at the forward end of the cylindrical projection; and said first chamber is disposed within a space defined by the end portion of the cylindrical projection and the abutting member.
 4. A sprayer according to claim 3 in which said second valve has a rod extending through the extension of the piston and is operative to urge the first valve toward the abutting member when the piston is moved into closest proximity to the closed end of the cylinder.
 5. A sprayer according to claim 4 in which said piston has a peripheral wall by which an annular space between the cylinder and the cylindrical projection is made minimal when the piston is moved into closest proximity to the closed end of the cylinder.
 6. A sprayer according to claim 5 in which said piston has at one end thereof an outwardly flared sealing portion and annular groove and said cylinder has at the closed end thereof an annular projection adapted to be fitted into the annular groove to push the sealing portion outward.
 7. A sprayer according to claim 1 in which a swirl means is further provided adjacent to the cap member, said swirl means defining another liquid chamber between the second valve and the cap member and imparting a swirling movement to the liquid.
 8. A sprayer according to claim 7 in which said cap member is slidably mounted at the forward end portion of the piston whereby when the distance between the swirl means and the cap member is adjusted the angle at which the liquid is squirted from the nozzLe is varied. 